Mooring of a floating unit to a vessel side

ABSTRACT

A mooring system ( 28 ) of a floatable unit ( 20 ), such as life raft or platform, the floatable unit ( 20 ) having a first side ( 21 ) facing a vessel side ( 22 ) and a second side ( 23 ) facing away from the vessel side ( 22 ). The mooring system ( 28 ) comprises at least two back springs ( 2 ) which are in connection with the first side ( 21 ) of the floatable unit ( 20 ), and at least one strap ( 1 ) which is in connection with the second side ( 23 ) of the floatable unit ( 20 ), the back springs ( 2 ) and the strap ( 1 ) being connected to the vessel ( 30 ). The back springs ( 2 ) are adapted to control the floatable unit ( 20 ) in a longitudinal direction in relation to the vessel ( 30 ), and the strap ( 1 ) is adapted to control the floatable unit ( 20 ) in a transverse direction in relation to the vessel ( 30 ). The floatable unit is held in secure and fixed position alongside the vessel side, thereby enabling people evacuating from the vessel to enter the floatable unit without any high risk of injury or damage.

This is a 35 U.S.C. 371 application of PCT/DK02/00678, filed on Oct. 9,2002, which claims the benefit of priority to Danish Application No. PA2002-00498 filed Apr. 4, 2002, each of which being incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates to a floatable unit, such as liferaft orplatform, having a first side facing a vessel side and a second sidefacing away from the vessel side, said floatable unit comprising amooring system.

The invention also relates to a mooring system for floatable units.

The term vessel is in this context to be construed as being a marineinstallation, such as vessel, ship, boat or offshore installation.

BACKGROUND ART

Floatable units, such as liferafts or platforms are often used in theevacuation of the passengers or crew members from a vessel.

Heeling movements as well as the movements which are caused by the loadssuch as wind, current or waves, exerted on the vessel render that theposition as well as the movements of the vessel are changing all thetime. Furthermore, due to the fact that the floatable unit is smaller insize than the vessel the floatable unit moves more rapidly than thevessel.

These movements of the vessel, as well as of the floatable unit arecausing the difficulties of entering the floatable unit from the vessel,as the distance, both in height, in the transverse as well as in thelongitudinal, direction between the vessel and the floatable unit isvarying constantly, whereby it is almost impossible to hold thefloatable unit in a secure and fixed position in relation to the vessel.

Often the evacuation of the persons from the vessel takes place duringheavy weather, which furthermore influences as well as exerts greatforces and loads on the vessel and the floatable unit.

Furthermore, the deck of the vessel, where the evacuation of the personstakes place from are normally placed above the waterline, and therebyabove the floatable unit, and may have many different distancesdepending on the size of the vessel.

The evacuation from the vessel into the floatable unit may be carriedout by means of many different arrangements, typically a slide or achute. More and more often the so called chute is used. The reason forthis is that the chute as a vertical escape route is arranged to absorbthe vertical variation of the distance between the evacuation point onthe vessel and the floatable unit.

If there is a large vertical distance between the deck of the vessel andthe floatable unit, and if this distance vary frequently during theevacuation, the chute, in it self is able to absorb this varyingdistance, due to its length and its thereby build-in flexibility.

However, in the cases where the distance between the deck of the vesseland the floatable unit is limited, a shorter chute might be used. Inthis case, the longitudinal displacement of the raft in relation to thevessel, will cause the chute to be inclined to such an extent that thechute becomes occasionally unusable.

The above-mentioned drawbacks and disadvantages are primarily explainedin connection with the vertical distance. However, similar drawbacks anddisadvantages occur in relation to the transverse and longitudinaldistances between the evacuation point of the vessel and the floatableunit.

Some known mooring systems consist of two lines which extends from awinch placed on the deck of the vessel and down to separate guidingpoints, placed on the vessel side above the waterline and towards theliferaft. The turning points are placed in a mutual distance larger thanthe length of the inflatable raft. The lines are fixed at each corner ofthe liferaft by means of a glued or welded attachment arrangement.

The known mooring systems have the disadvantage that when the liferaftsshall be pulled into the vessel side to evacuate passengers down in theraft great pulling forces have to be used, which affect the area wherethe lines are fixed. Whereby the raft is easily destroyed in the areaaround the fixed point for the mooring lines.

The pulling forces in the fixed point for the line are increased furtherwhen the vessel and the raft are placed differently in relation to wavetrough and wave crest.

SUMMARY OF THE INVENTION

An object of the present invention is to wholly or partially overcomethe above disadvantages of the prior art. More specifically, it is anobject to provide a floatable unit, which can be securely positionedalongside a vessel during evacuation of passengers or crew members.

It is furthermore an object of the invention to provide a mooring systemfor a floatable unit, which system in expedient manner is adapted tocontrol the longitudinal as well as the transverse movements of thefloatable unit in relation to a vessel.

The above objects, together with numerous other objects, advantages andfeatures which will become evident from the below description, areaccomplished by a solution in accordance with the present invention bythe mooring system comprising at least two back springs which are inconnection with the first side of the floatable unit, said springs beingadapted to control the floatable unit in a longitudinal direction inrelation to the vessel. The system furthermore comprises at least onestrap, which is in connection with the second side of the floatableunit, said strap being adapted to control the floatable unit in atransverse direction in relation to the vessel, and said back springsand said strap being connected to the vessel.

The new system has the advantage, that the forces on the raft aredistributed over a larger area and that it is easier to control the raftin relation to either the movements, which emanates from the vessel orthe longitudinal movements, which are caused by the difference of heightbetween wave crest and wave trough as well as the movements, which arecaused by current and wind load.

Furthermore by having the floatable unit in expedient manner held in thesecure and fixed position alongside the vessel side it is obtained thatthe people, who are going to be evacuated from the vessel, are able toenter the floatable unit without any high risk for personnel damage.Additionally, the secure and fixed position of the floatable unit makesit more pleasant for the people to stay and work in the floatable unitduring the mooring to the vessel, due to the fact that the movements ofthe floatable unit are controlled to a minimum.

It should however be mentioned that the heavy weather conditions such asstrong wind, high wave height and strong current makes conditions almostinhuman, as the floatable unit will have large and uncomfortablemovements relating to the vessel. However, the solution according to theinvention is minimising the above mentioned movements of the floatableunit which have been surprising for the skilled person.

A further advantage by the solution of the present invention is that thesystem may be used with both short and long evacuation means, as thefloatable unit is held in a fixed secure position.

During operation of the floatable unit wherein it is moored to thevessel side, the back springs, which are in connection with the side ofthe floatable unit facing the vessel, secure that the floatable unit iscontrolled in the longitudinal direction in relation to the vessel. Theback springs extend, as will be appreciated by a skilled person, fromthe first side of the floatable unit alongside the side towards thevessel, so that the back springs substantially extend parallel inrelation to sides of the floatable unit and the vessel. Hereby, the backsprings will control the mutual longitudinal movements of the floatableunit and the vessel, so that the floatable unit is essentially held in afixed position in the longitudinal direction in relation to the vessel.Both of the back springs extend from the side of the floatable unitoutward past the ends of the floatable towards the vessel.

Furthermore, the strap extends from the second side of the floatableunit, which side is facing away from the vessel, towards the vessel.Hereby the strap is secured under operation that the floatable unit iscontrolled in the transverse direction in relation to the vessel. Thestrap extends essentially perpendicular from the vessel towards thesecond side of the floatable unit. The strap furthermore extends fromthe second side of the floatable unit past both ends of the floatableunit towards the vessel in order to hold the floatable unit in a secureand fixed position.

The term back spring is in this context to be construed as being a rope,strap, belt or wire. The back springs may be produced of an arbitrarymaterial, which has sufficient strength for holding the raft. The backsprings are in a preferred embodiment produced of strong woven material.

The term strap is in this context to be construed as being a rope, beltor wire. The strap may be produced by an arbitrary material, which hassufficient strength for keeping the raft towards the vessel side.

In an expedient embodiment according to the invention the mooring systemmay comprise at least two mooring lines which are in connection with thestrap and the back springs, respectively, said mooring lines beingconnected to the vessel. According to the invention, a plurality ofmooring lines may be arranged between the vessel and the floatable unit.In a preferred embodiment two mooring lines are arranged, whereby it isobtained, that only one mooring line at each end of the floatable unitis connected to the vessel, whereby an easier handling of the mooringsystem is also obtained.

Advantageously according to the invention there may be arranged at leastone flexible element between the mooring lines and the strap and/orbetween the mooring lines and the back springs. Thus it is obtained thatthe flexible element is taking up or absorbing the tensile stresses inthe back springs, strap or mooring lines which are caused by the mutualmovements between the floatable unit and the vessel. A further advantageis that strong pulls in the back springs, strap or mooring lines areavoided and thereby the back springs, strap or mooring lines may bemaintained at a considerably lower level of tension. The fact is thatthe movements of the floatable unit in relation to the vessel is almosteliminated by this system.

The term flexible element is in this context to be construed as being anelement arranged for absorbing tensile stresses in the mooring systemand may for instance be made of an elastic material, be an elastic orrubber rope or be a spring.

Further according to the invention a flexible element may be arranged atthe ends of the back springs and/or at the ends of the strap facing thevessel, whereby each element in the system can absorb the forces exertedon them.

In a preferred embodiment according to the invention the strap maybelead alongside the second side, so as to provide an encircling of thefloatable unit, and each end of the strap is connected to the vessel. Bythis encircling of the floatable unit by the strap a secure way to holdthe floatable unit in a fixed position obtained. Furthermore, thepulling forces exerted on the strap, which in the known floatable unitsare absorbed by the attachments onto which the strap is fixed, may beabsorbed by the entire second side of the floatable unit. The fact isthat the exerted forces absorbed by the strap are pushing the floatableunit against the vessel, rather than as the prior art pulling the strapaway from the floatable unit, with the result of damaging theattachment.

According to the present invention the mooring system comprises twostraps, in which one end of the straps are fixed to the second side ofthe floatable unit and the other end of the straps are connected to thevessel.

According to a preferred embodiment according to the present inventionthe back springs may be fixed substantially to the centre of the firstside and extend outward towards the vessel. By this fixation of the backsprings it is obtained that the back springs substantially extendsparallel in relation to the sides of the floatable unit and the vessel.

Advantageously the strap according to the invention may be held inposition on the second side by strap attachments, in which the strap isable to move sideways. Hereby it is obtained that the floatable unit isnot exerted by any forces from the strap, as the strap in thisembodiment is not securely fixed in the attachments. Thus the floatableunit is wrapped or encircled by the strap.

The strap may in an arbitrary way be fixed around the raft, but in apreferred embodiment it is held in position by strap attachments, whichare placed on the side of the raft, which is facing away from the vesselside as well as on the two longitudinal sides.

In an expedient embodiment according to the invention the floatable unitmay be inflatable, and the floatable unit may comprise at least twoinflatable chambers arranged on top of each other. The inflatablefloatable unit, such as liferaft or platform, may comprise a peripheraledge having at least one inflatable chamber surrounding a bottom securedin leak tight fashion to the tubular inflatable chambers. Due tosecurity reasons the inflatable floatable unit comprises at least twochambers, whereby if one of the chambers are not functioning, the otherwill have the necessary buoyancy to keep the floatable unit floating.

According to the invention the strap attachments may be placed so as itextends from the first chamber to the second chamber of the floatableunit.

In a further preferred embodiment the strap attachment is placed so thatit extends from a first chamber to a second chamber for distributing theforces between the two chambers and to avoid that the buoyancy chambersare separated.

The present invention furthermore concerns a mooring system for afloatable unit, such as liferaft or platform, said floatable unit havinga first side facing a vessel side and a second side facing away from thevessel side. Wherein the mooring system is characterised in that it maycomprise at least two back springs which are in connection with thefirst side of the floatable unit, said springs being adapted to controlthe floatable unit in a longitudinal direction in relation to thevessel, at least one strap which is in connection with the second sideof the floatable unit, said strap being adapted to control the floatableunit in a transverse direction in relation to the vessel, and said backsprings and said strap being connected to the vessel.

Advantageously at least two mooring lines may be arranged, said mooringlines are in connection with the strap and the back spring,respectively. And between the mooring lines and the strap and/or betweenthe mooring lines and the back springs there may be arranged at leastone flexible element.

Finally, the present invention also concerns the use of a mooring systemfor a floatable unit, such as liferaft or platform, said floatable unithaving a first side facing a vessel side and a second side facing awayfrom the vessel side, the mooring system comprises at least two backsprings which are in connection with the first side of the floatableunit, said back springs being adapted to control the floatable unit in alongitudinal direction in relation to the vessel, at least one strapwhich is in connection with the second side of the floatable unit, saidstrap being adapted to control the floatable unit in a transversedirection in relation to the vessel, and said back springs and saidstrap being connected to the vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its advantages will be described in more detail belowwith reference to the accompanying schematic drawings, which by way ofexample illustrate currently preferred embodiments of the invention.

FIG. 1 shows in a side view an embodiment of the mooring systemaccording to the invention.

FIG. 2 shows the system of FIG. 1 seen alongside a vessel side.

FIG. 3 shows the system according to FIGS. 1 and 2 seen from above.

FIG. 4 shows in detail a first embodiment of the flexible elementaccording to the invention.

FIG. 5 shows in detail a second embodiment of the flexible elementaccording to the invention.

FIG. 6 shows in detail an embodiment of some attachments according tothe invention.

FIG. 7 shows in detail an embodiment of the strap attachments accordingto the invention.

FIGS. 8 a–8 e shows the function of the floatable unit having a mooringsystem according to the invention.

All the figures are highly schematic and not necessarily to scale, andthey show only parts which are necessary in order to elucidate theinvention, other parts being omitted or merely suggested.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the shown example the evacuation of the passengers or crew memberstakes place from the vessel by means of a chute, the evacuation from thevessel into the raft is independent of the mooring system, and may thustake place by means of a slide, a rope, ladders, jumps or in other ways.

The mooring system will be described in an embodiment, which in no wayshall be considered as limiting for the invention.

In FIG. 1 the floatable unit 20 is shown, here in the form of aninflatable liferaft. According to the invention the floatable unit mayalso be a platform or a MOB-boat (man over board).

The floatable unit 20 has a first side 21 facing a vessel side 22 and asecond side 23 facing away from the vessel side 22. The inflatablefloatable unit 20 furthermore comprises a peripheral edge having twoinflatable chambers 25, 26 surrounding a bottom (not shown) secured inleak tight fashion to the tubular inflatable chambers. The floating unit20 also comprises a canopy 27, so as to provide shelter for theevacuated persons.

A mooring system 28 having at least two back springs 2 which are inconnection with the first side 21 of the floatable unit 20, said backsprings 2 being adapted to control the floatable unit 20 in alongitudinal direction in relation to the vessel 30.

Furthermore, the mooring system 28 comprises at least one strap 1 whichis in connection with the second side 23 of the floatable unit 20, saidstrap 1 being adapted to control the floatable unit 20 in a transversedirection (arrow A) in relation to the vessel 30. The back springs 2 andthe strap 1 are connected to the vessel 30 via mooring line 32.

In connection with the strap 1 a flexible element 3 is arranged and inconnection with the back springs 2 a flexible element 3 is also arrangedfor absorbing the tensile stresses in the strap 1 and the back springs2.

The mooring line 32 is connected to the strap 1 and the back springs 2via guiding point 35 placed on the vessel side 22 above the water line.The mooring line 32 is furthermore connected to a winch 36 placed on thedeck of the vessel 30.

In this embodiment according to the invention as mentioned above theevacuation of the persons on the vessel 30 takes place by means of achute 40. The function of the chute 40 is well known in the art and willtherefore not be explained in further detail.

FIG. 2 shows the floatable unit 20 seen alongside the vessel side 22. Inthis figure it is seen that the mooring system comprises two mooringlines 32, which are connected to the vessel 30.

The mooring system also consists of the strap 1, which is placed outsidearound the raft 20 held in position in strap attachments 12, which isplaced on the side 23 of the raft 20, which is facing away from thevessel side 22 as well as on the two longitudinal sides.

The strap attachments 12 are in the shown embodiment placed so that theyextend from a first chamber 26 to a second chamber 25 for distributingthe forces between the two chambers and to avoid that the buoyancychambers are separated.

The strap 1 is in its ends 41 arranged with a flexible element 3, whichin the shown embodiment is a thick elastic rope, which is wrapped withropes. The ropes shall function as a stop rope, which secures that theelastic is not burst. The strap 1 and the flexible element 3 isconnected to each other through a P-joint 4. The flexible element 3 willbe explained more detailed below.

The back springs can in this embodiment not be seen. However, inrelation to the ends of the back springs further flexible elements 3′are arranged. The flexible elements 3′ of the back springs and theflexible elements 3 of the strap 1 are connected to the mooring lines32, which are lead to the vessel by means of the guiding points 35. Theguiding points 35 are in expedient manner placed in mutual distancegreater than the length of the floatable unit 20, whereby a secure wayof holding the floatable unit 20 in position is obtained.

FIG. 3 shows the floatable unit 20 from above. The strap 1 is leadalongside the second side 23 of the floatable unit 20, so as to providean encircling of the floatable unit 20, and each end 41 of the strap 1is connected to the vessel.

This encircling or wrapping of the floatable unit 20 provides a secureway to hold the floatable unit 20 in a fixed position. Furthermore, thepulling forces exerted on the strap 1 may be absorbed by the entiresecond side 23 of the floatable unit 20. The fact is that the exertedforces absorbed by the strap 1 is pushing the floatable unit against thevessel, rather than as the prior art pulling the strap 1 away from thefloatable unit 20, with the result of damaging the attachment.

Furthermore the mooring system consists of two back springs 2, whichabsorb the movements of the raft alongside the vessel side 22. The backsprings 2 are in the shown embodiment arranged at the centre 42 of theraft 20 on the side 21 of the raft 20, which are facing the vessel side22. The back springs 2 being adapted to control the floatable unit 20 ina longitudinal direction (arrow B) in relation to the vessel 30.

The floatable unit 20 is in this embodiment shown substantially ashaving four sides. However, the floatable may inside the inventiveconcept have many different designs or shapes, such as for instanceround or have a plurality of sides.

In FIG. 4 an embodiment of the flexible element 3 according to theinvention is shown. The flexible elements 3, which extends from thestrap 1 and the back spring 2, respectively, are assembled in an O-ring5. Between the O-ring 5 and the mooring lines is a relay 6, which cutsthe lines between the vessel and the raft in case the vessel is sinkingarranged by means of a shackle 7.

The relay may for instance be a Hydrostatic release unit, which isadapted to automatically make the liferafts container float free whenthe release unit reaches a dept of water of for example 2–4 meters. Ifthe vessel sinks, the water pressure will activate a sharp knife thatcuts the strong rope and the floatable unit will float free. The relayis in this embodiment placed at the assembly of the mooring lines andthe strap and back springs, but could also be arranged in other placesin the floatable unit, which will be appreciated by the skilled person.

The back springs 2 are, in the same manner as the strap 1, at their endsarranged with a flexible element 3, which in the shown embodiment is athick elastic rope, which is wrapped by a rope. The rope shall functionas a stop rope which secures that the elastic does not burst. The backspring 2 and the flexible element 3 are connected to each other througha P-joint 4.

FIG. 5 shows another embodiment of the flexible element 3, wherein aheavy rubber band or rope 43 makes the element elastic and in the sameway as explained above in relation to FIG. 4, is the band wrapped by astop rope 44.

In FIG. 6 an embodiment of the back springs attachment is shown. Theback springs are fixed in a four-leaf clover attachment 10, theattachment 10 is mutually connected by the rope 11 as shown in FIG. 6,the back springs are connected to this rope 11 on the line distance 13and 14, respectively. The four-leaf clover attachment 10 is placed insuch a way that it extends from the first chamber to the second chamberfor distributing the pull forces between the buoyancy chambers.

As shown in FIG. 6 the rope 11 is furthermore connected through the twoattachments 9, on the top side of the second chamber under the rope 11,between the two attachments 9, a cut plate 8 might be placed if deemednecessary on which it is possible to cut the raft free from the vesselwithout damaging the raft. The embodiment shown in FIG. 6 secures thatthe persons in the floatable unit can release the floatable unit fromthe mooring system and thereby the vessel without leaning out of orleaving the unit. Hereby it is obtained that the persons in thefloatable unit do not have to work between the sides of the vessel andthe floatable unit.

FIG. 7 shows an example of the strap attachments 12 wherein the strap 1is held in position, and in which the strap 1 is able to move sideways.The strap attachments 12 are placed so that they extend from the firstchamber 26 to the second chamber 25 of the floatable unit.

In FIGS. 8 a–8 e the floatable unit is having a mooring system accordingto invention shown during operation.

In FIG. 8 a a vessel side is shown, in this situation a container 50containing an inflatable liferaft is not released from the vessel.

In FIG. 8 b the container 50 is released from the vessel and floats inthe water. Furthermore, it is seen that the mooring lines are beingreleased from their attachments on the vessel side.

In FIG. 8 c the container 50 is brought in position below the enteringplace 51 on the vessel. The mooring lines 32 are now completely releasedfrom their attachments and are from the two winches 52 connected to thecontainer 50 via guiding points 35.

In FIG. 8 d the liferaft 20 is contained in the container beinginflated. Furthermore, the mooring lines 32 are being connected toflexible elements 3 which according to the inventive idea are arrangedat the ends of the back springs and the strap. Hereby the liferaft isbeing held in position below the entering point.

In FIG. 8 e the liferaft is completely inflated and ready to be enteredby the persons, who are to be evacuated from the vessel.

By using the mooring system according to the invention for a floatableunit, such as a liferaft it is obtained that the liferaft during use canbe held in a secure and fixed position and thereby minimise thediscomfort for persons being in and working on the liferaft duringmooring to the vessel. A further advantage by using the inventivemooring system is that the high pulling forces which are exerted on theliferaft, especially via the transverse movements, do not damage thestrap attachments by pulling them of.

Although the invention above has been described in connection withpreferred embodiments of the invention, it will be evident for a personskilled in the art that several modifications are conceivable withoutdeparting from the invention as defined by the following claims.

1. A floatable unit having a first side facing a side of a vessel and asecond side facing away from the side of the vessel, said floatable unitcomprising a mooring system, wherein the mooring system comprises: twoback springs which are in connection with the first side of thefloatable unit, said two back springs being adapted to control thefloatable unit in a longitudinal direction in relation to the vessel;and a strap which is in connection with the second side of the floatableunit, said strap being adapted to control the floatable unit in atransverse direction in relation to the vessel, and said two backsprings and said strap being connected to the vessel.
 2. A floatableunit according to claim 1, wherein the mooring system comprises twomooring lines which are in connection with the strap and the two backsprings, respectively, said mooring lines being connected to the vessel.3. A floatable unit according to claim 2, wherein a flexible element isarranged between the two mooring lines and at least one of the strap andthe two back springs.
 4. A floatable unit according to claim 2, whereinthe strap has ends and the two back springs have ends, the flexible unitfurther comprising: a flexible element arranged in at least one of theends of the two back springs and/or the ends of the strap facing thevessel.
 5. A floatable unit according to claim 1, wherein the strap islead alongside the second side of the floatable unit to encircle thefloatable unit, the strap having ends and each of the ends of the strapis connected to the vessel.
 6. A floatable unit according to claim 1,wherein the strap is a first strap having first and second ends, themooring system further including a second strap having first and secondends first ends of the first and second straps being fixed to the secondside of the floatable unit and the second ends of the first and secondstraps being connected to the vessel.
 7. A floatable unit according toclaim 1, wherein the two back springs are fixed substantially to acenter of the first side and extends outward towards the vessel.
 8. Afloatable unit according to claim 1, wherein the strap is held inposition on the second side of the floatable unit by strap attachments,in which the strap is moveable sideways.
 9. A floatable unit accordingclaim 8, wherein the strap attachments extends from a first inflatablechamber to a second inflatable chamber of the floatable unit.
 10. Afloatable unit according to claim 1, wherein the floatable unit isinflatable, and the floatable unit comprises at least two inflatablechambers arranged vertically.
 11. A mooring system for a floatable unit,said floatable unit having a first side facing a side of a vessel and asecond side facing away from the side of the vessel wherein, the mooringsystem comprises: two back springs which are in connection with thefirst side of the floatable unit, said two back springs being adapted tocontrol the floatable unit in a longitudinal direction in relation tothe vessel; and a strap which is in connection with the second side ofthe floatable unit, said strap being adapted to control the floatableunit in a transverse direction in relation to the vessel, and said twoback springs and said strap being connected to the vessel.
 12. A mooringsystem according to claim 11, further comprising two mooring lines inconnection with the strap and the two back springs, respectively.
 13. Amooring system according to claim 12, further comprising a flexibleelement arranged between the two mooring lines and at least one of thestrap and the two back springs.
 14. A mooring system for a floatableunit, said floatable unit having a first side facing a side of a vesseland a second side facing away from the side of the vessel, the mooringsystem comprising: two back springs in connection with the first side ofthe floatable unit, said two back springs being adapted to control thefloatable unit in a longitudinal direction in relation to the vessel;and a strap being connected to the second side of the floatable unit,and being adapted to control the floatable unit in a transversedirection in relation to the vessel, the two back springs and said strapbeing connected to the vessel.